Patentable/Patents/US-20260040839-A1
US-20260040839-A1

Methods of Epitaxially Growing Boron-Containing Structures

PublishedFebruary 5, 2026
Assigneenot available in USPTO data we have
Technical Abstract

Embodiments of the present invention generally relate to methods of epitaxially growing boron-containing structures. In an embodiment, a method of depositing a structure comprising boron and a Group IV element on a substrate is provided. The method includes heating the substrate at a temperature of about 300° C. or more within a chamber, the substrate having a dielectric material and a single crystal formed thereon. The method further includes flowing a first process gas and a second process gas into the chamber, wherein: the first process gas comprises at least one boron-containing gas comprising a haloborane; and the second process gas comprises at least one Group IV element-containing gas. The method further includes exposing the substrate to the first and second process gases to epitaxially and selectively deposit the structure comprising boron and the Group IV element on the single crystal.

Patent Claims

Legal claims defining the scope of protection, as filed with the USPTO.

1

the substrate is positioned within the substrate processing chamber, the substrate has a dielectric material and a crystalline material formed thereon, and the crystalline material comprises a Group IV element; 2 6 3 3 the first process gas comprises diborane (BH) and boron trichloride (BCl), and the BClflows at a flow rate within a range of 1 sccm to 100 sccm, and the second process gas comprises at least one Group IV element-containing gas; and flowing a first process gas and a second process gas into a substrate processing chamber, wherein: 20 3 exposing the substrate to the first process gas and the second process gas to epitaxially and selectively deposit the structure comprising boron and the Group IV element on the crystalline material, the structure having a boron concentration of 5×10atoms/cmor more. . A method of depositing a structure on a substrate, the method comprising:

2

claim 1 21 . The method of, wherein the boron concentration is 1×10or more.

3

claim 1 . The method of, wherein the first process gas and the second process gas selectively deposit the structure at a growth rate of 100 Å/min or more.

4

claim 1 . The method of, further comprising heating the substrate to a temperature of 300° C. or more.

5

claim 1 3 . The method of, wherein the flow rate of the BClis within a range of 1 sccm to 30 sccm.

6

claim 5 3 . The method of, wherein the flow rate of the BClis within a range of 1 sccm to 10 sccm.

7

claim 1 . The method of, wherein the first process gas is flown into the substrate processing chamber and is exposed to the substrate prior to flowing the second process gas into the substrate processing chamber.

8

claim 1 . The method of, further comprising co-flowing the first process gas and the second process gas into the substrate processing chamber after exposing the substrate to the first process gas.

9

claim 1 . The method of, wherein the second process gas comprises Si, Ge, or a combination thereof.

10

claim 1 3 3 4 10 5 9 5 11 6 10 6 12 10 14 3 3 3 2 3 2 3 3 2 2 3 2 2 3 3 2 3 3 6 5 3 . The method of, wherein the first process gas further comprises one or more of: borane (BH), triborane (BH5), tetraborane (BH), pentaborane (9) (BH), pentaborane (11) (BH), hexaborane (10) (BH), hexaborane (12) (BH), decaborane (14) (BH), trimethylborane ((CH)B), dimethylborane ((CH)BH), triethylborane ((CHCH)B), diethylborane ((CHCH)BH), tripropylborane ((CHCHCH)B), or tributylborane ([CH(CH)]B), triphenylborane ((CH)B).

11

claim 1 . The method of, wherein the structure has an amount of germanium (Ge) that is from 10 atomic % to 70 atomic %.

12

heating the substrate at a temperature of 300° C. to 700° C., the substrate positioned within a substrate processing chamber, the substrate having a dielectric material and a single crystal formed thereon, and the single crystal comprising Si, Ge, or a combination thereof; and 2 6 3 the first process gas comprises diborane (BH) and boron trichloride (BCl), the second process gas comprises at least one Group IV element-containing gas, and 2 2 the carrier gas comprises H, N, or a combination thereof; and flowing a first process gas, a second process gas, and a carrier gas into the substrate processing chamber, wherein: 20 3 exposing the substrate to the first process gas and the second process gas to epitaxially and selectively grow the structure, the structure having a boron concentration of 5×10atoms/cmor more. epitaxially and selectively growing the structure on the single crystal, the structures comprising boron and a Group IV element, and the growing comprising: . A method of growing a structure on a substrate, the method comprising:

13

claim 12 3 . The method of, wherein the BClflows at a flow rate within a range of 1 sccm to 100 sccm, and the first process gas and the second process gas selectively deposit the structure at a growth rate of 100 Å/min or more.

14

claim 12 n is 0; and each X is, independently, Cl or Br. . The method of, wherein:

15

claim 12 3 3 5 4 10 5 9 5 11 6 10 6 12 10 14 . The method of, wherein the first process gas further comprises one or more of: borane (BH), triborane (BH), tetraborane (BH), pentaborane (9) (BH), pentaborane (11) (BH), hexaborane (10) (BH), hexaborane (12) (BH), or decaborane (14) (BH).

16

claim 12 . The method of, wherein the at least one Group IV element-containing gas has the formula: 1 2 each of Mand Mis, independently, Si or Ge; 3 1 6 each Ris, independently, a halogen or a C-Calkyl group; x is 1, 2, 3, or 4; y is 1, 2, 3, or 4; and z is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. wherein:

17

claim 12 . The method of, wherein the at least one Group IV element-containing gas comprises a silane, a germane, or a combination thereof having the formula: 1 Mis Si or Ge; and x is 1, 2, 3, or 4. wherein:

18

claim 12 co-flowing the first process gas and the second process gas into the substrate processing chamber after flowing the first process gas into the substrate processing chamber and exposing the first process gas to the substrate. . The method of, wherein the first process gas is flown into the substrate processing chamber and is exposed to the substrate prior to flowing the second process gas into the substrate processing chamber, and the method further comprises

19

2 6 3 3 flowing a first boron-containing gas into the substrate processing chamber, the first boron-containing gas comprising diborane (BH) and boron trichloride (BCl), the BClflowing at a flow rate within a range of 1 sccm to 100 sccm; exposing the substrate with the first boron-containing gas; co-flowing a second boron-containing gas and at least one Group IV element-containing gas into the substrate processing chamber, the first boron-containing gas and the second boron-containing gas being the same or different; and 20 3 exposing the substrate with the second boron-containing gas and the Group IV element-containing gas to epitaxially and selectively grow the structure, the structure having a boron concentration of about 5×10atoms/cmor more. epitaxially and selectively growing the structure on the substrate positioned within a substrate processing chamber, the substrate having a dielectric material, the structure comprising boron and the Group IV element, and the growing comprising: . A method for growing a structure on a substrate, the method comprising:

20

claim 19 . The method of, wherein the first boron-containing gas is flown into the substrate processing chamber and is exposed to the substrate prior to co-flowing the second boron-containing gas and the at least one Group IV element-containing gas into the substrate processing chamber.

Detailed Description

Complete technical specification and implementation details from the patent document.

This application is a continuation of U.S. patent application Ser. No. 17/573,748, filed Jan. 12, 2022, which is herein incorporated by reference in its entirety.

Embodiments of the present invention generally relate to methods of epitaxially growing boron-containing structures for use in, e.g., P-channel metal-oxide-semiconductor (pMOS) films.

Selective epitaxial deposition of, e.g., silicon (Si), permits the growth of epitaxial layers on exposed crystalline planes (e.g., Si, Ge, or other semiconductor regions) of a substrate, also known as deposition or depositing of the layers, with no net film growth on exposed dielectric areas of the substrate. Selective epitaxy can be used in the fabrication of semiconductor device structures, such as for forming desired layers in elevated source/drains, source/drain extensions, contact plugs, and base layers of bipolar devices.

20 3 20 3 20 3 The selectivity of an epitaxial process is determined by the sources of elements to be deposited, e.g., the source of boron (B), Si, and/or germanium (Ge) elements, as well as the etchant utilized to suppress film nucleation on dielectric features. With respect to fabrication of pMOS epitaxial films, conventional processes utilize diborane (B2H6) as the source of boron. However, B2H6 decomposes easily upon thermal heating and leads to poor selectivity as the boron deposits on the dielectric areas of the substrate. Such selectivity loss, as well as crystalline film degradation, is worse at high boron source concentrations (>3×10atoms/cm). For example, conventional selective SiGeB processes utilizing dichlorosilane (DCS), germane (GeH4), B2H6, and HCl, can achieve boron concentrations in the film up to about 2-3×10atoms/cm. To achieve boron concentrations in the film >3×10atoms/cm, more B2H6 is utilized. However, higher etchant amounts are required to maintain selectivity. In addition, boron-rich non-epitaxial layers easily form on crystalline Si and SiGe surfaces, which negatively affects pMOS crystalline film growth with time.

There is a need for new and improved methods of depositing boron that overcome these and other deficiencies in the art.

Embodiments of the present invention generally relate to methods of epitaxially growing boron-containing structures.

n 3-n 1 6 1 1 20 3 In an embodiment, a method of depositing a structure comprising boron and a Group IV element on a substrate is provided. The method includes positioning the substrate within a substrate processing chamber, the substrate having a dielectric material and a single crystal formed thereon, the single crystal comprising a Group IV element; and heating the substrate at a temperature of about 300° C. or more. The method further includes flowing a first process gas and a second process gas into the substrate processing chamber, wherein: the first process gas comprises at least one boron-containing gas, the at least one boron-containing gas comprising a haloborane of formula: BRX, wherein: each Ris, independently, hydrogen or a C-Calkyl group; each X is a halogen; and n is 0, 1, or 2; and the second process gas comprises at least one Group IV element-containing gas. The method further includes exposing the substrate to the first process gas and the second process gas to epitaxially and selectively deposit the structure comprising boron and the Group IV element on the single crystal, the structure having a boron concentration of about 3×10atoms/cmor more.

n 3-n 1 6 2 2 1 1 20 3 In another embodiment, a method of epitaxially and selectively growing a structure comprising boron and a Group IV element on a substrate is provided. The method includes positioning the substrate within a substrate processing chamber, the substrate having a dielectric material and a single crystal formed thereon, the single crystal comprising Si, Ge, or a combination thereof; and heating the substrate at a temperature of about 300° C. to about 700° C. The method further includes epitaxially and selectively growing the structure comprising boron and the Group IV element on the single crystal, comprising: flowing a first process gas, a second process gas, and a carrier gas into the substrate processing chamber, wherein: the first process gas comprises at least one boron-containing gas, the at least one boron-containing gas comprising a haloborane having the formula: BRX, wherein: each Ris, independently, hydrogen or a C-Calkyl group; each X is a halogen; and n is 0, 1, or 2; the second process gas comprises at least one Group IV element-containing gas; and the carrier gas comprises H, N, or a combination thereof; and exposing the substrate to the first process gas and the second process gas to epitaxially and selectively grow the structure, the structure having a boron concentration of about 3×10atoms/cmor more.

20 3 In another embodiment, a method for epitaxially and selectively growing a structure comprising boron and a Group IV element on a substrate is provided. The method includes positioning the substrate within a substrate processing chamber, the substrate having a dielectric material and a single crystal formed thereon; and heating the substrate at a temperature of about 300° C. to about 700° C. The method further includes epitaxially and selectively growing the structure comprising boron and the Group IV element on the single crystal, comprising: flowing a first boron-containing gas into the substrate processing chamber, the first boron-containing gas comprising a haloborane; exposing the substrate with the first boron-containing gas; co-flowing a second boron-containing gas and at least one Group IV element-containing gas into the substrate processing chamber, the first boron-containing gas and the second boron-containing gas being the same or different; and exposing the substrate with the second boron-containing gas and the Group IV element-containing gas to epitaxially and selectively grow the structure, the structure having a boron concentration of about 3×10atoms/cmor more.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

20 3 20 3 Embodiments of the present invention generally relate to methods of epitaxially growing boron-containing structures. The methods described herein enable improved selectivity and higher concentrations of dopants (e.g., boron) deposited in, e.g., pMOS films relative to conventional processes. The methods described herein can be utilized for, e.g., 3-nm process nodes, 2-nm process nodes, and source/drain applications. As described above, conventional pMOS processes utilize diborane as a boron source for epitaxial deposition of pMOS films. Such epitaxial deposition processes, however, can suffer from low selectivity and lower-than-desired boron concentrations in the deposited pMOS film. In contrast, and in some examples, methods described herein can utilize a different boron source (e.g., BCl3 and/or other boron sources) as a process gas instead of diborane alone. Utilization of the different boron source can achieve, e.g., better selectivity, better growth rates, and higher boron concentrations in the pMOS films relative to diborane alone, especially meaningful for a variety of applications such as 3-nm process nodes, 2-nm process nodes, and source/drain applications. For example, boron concentrations greater than about >3×10atoms/cm, such as greater than >5×10atoms/cmcan be achieved by methods described herein, though higher or lower concentrations are contemplated.

3 3 x x 2 2 2 2 2 6 3 4 4 2 4 2 3 3 As a non-limiting example, the inventors have found that the use of BClenables higher selectivity relative to diborane as BClpassivates the dielectric surface (B—Cl bonded) and increases the reaction energy barrier for Group IV element (Si, Ge, etc.) nucleation on dielectric surfaces of the substrate. With respect to passivation of the dielectric surface of the substrate during epitaxial processes, both BHand BClform strong bonds to oxide surfaces (e.g., SiO). Once bonded to the oxide surface, the B—H bond of SiO—BHweakens whereas the B—Cl bond of SiO—BClstrengthens. Here, SiO-BHmoieties easily dissociate to Si—O—B whereas SiO—BClmoieties remain relatively stable, thereby acting to passivate the dielectric surface of the substrate. When comparing the energetics of BHand BClduring epitaxial processing with, e.g., silane (SiH), SiHabsorption on SiO—BHsites of the dielectric is favored, leading to poor selectivity. In contrast, SiHabsorption on SiO—BClsites of the dielectric is not favored, leading to improved selectivity. Further, BClis not as thermally active as B2H6, which reduces the likelihood of forming boron-rich layers on the crystalline planes of the substrate. In addition, more local Cl species forms in the reaction of BClwith Group IV element-containing gases on the crystalline surface (e.g., Si, SiGe, SiB, SiGeB, etc.), thereby improving the selectivity and pMOS film crystallinity.

For purposes of the present disclosure, the terms “structure,” “coating,” “layer,” “material,” and “film” are used interchangeably such that reference to one includes reference to the others. For example, reference to “structure” includes structure, coating, layer, material, and film unless the context indicates otherwise.

As used herein, a Group IV element of the periodic table of elements refers to carbon (C), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), or combinations thereof. For example, a Group IV element-containing structure can include, e.g., a C-containing structure, a Si-containing structure, a Ge-containing structure, a SiB-containing structure, a SiGeB-containing structure, and/or other structures. Group IV elements are also referred to as Group 14 elements of the periodic table of the elements.

For the purposes of this present disclosure, and unless otherwise specified, the term “alkyl” or “alkyl group” interchangeably refers to a group consisting of hydrogen and carbon atoms only. An alkyl group can be substituted or unsubstituted, saturated or unsaturated, linear or branched, cyclic or acyclic, aromatic or non-aromatic, or combinations thereof. When a number of carbon atoms of an alkyl group is specified herein, it is intended that the number refers to the exact number of carbon atoms, or range of carbon atoms, that is specified. In other words, when a number of carbon atoms (or range thereof) is specified for an alkyl group, it is not intended that the alkyl group comprises that specified number of carbon atoms, but rather that the alkyl group contains the specified number. For example, if an alkyl is specified to have or to contain 1 to 6 carbon atoms, an alkyl group having or containing 8 carbon atoms would not qualify; rather, only an alkyl group that contains 1, 2, 3, 4, 5, or 6 carbon atoms would qualify.

Reference to an alkyl group without specifying a particular isomer (e.g., butyl) expressly discloses all isomers (e.g., n-butyl, iso-butyl, sec-butyl, and tert-butyl). For example, reference to an alkyl group having 4 carbon atoms expressly discloses all isomers thereof. When a compound is described herein such that a particular isomer, enantiomer or diastereomer of the compound is not specified, for example, in a formula or in a chemical name, that description is intended to include each isomer and enantiomer of the compound described individual or in any combination.

2 2 2 2 2 x 2 3 3 3 3 2 2 2 2 1 10 “Substituted alkyl” refers to an alkyl, where at least one hydrogen of the alkyl has been substituted with at least one heteroatom or heteroatom-containing group, such as one or more elements from Group 13-17 of the periodic table of the elements, such as halogen (F, Cl, Br, or I), O, N, Se, Te, P, As, Sb, S, B, Si, Ge, Sn, Pb, and the like, such as C(O)R*, C(C)NR*, C(O)OR*, NR*, OR*, SeR*, TeR*, PR*, AsR*, SbR*, SR*, SO(where x=2 or 3), BR*, SiR*, GeR*, SnR*, PbR*, and the like or where at least one heteroatom has been inserted within the alkenyl radical such as one or more of halogen (Cl, Br, I, F), O, N, S, Se, Te, NR*, PR*, AsR*, SbR*, BR*, SiR*, GeR*, SnR*, PbR*, and the like, where R* is, independently, hydrogen, hydrocarbyl (e.g., C-C), or two or more R* may join together to form a substituted or unsubstituted completely saturated, partially unsaturated, fully unsaturated, or aromatic cyclic or polycyclic ring structure.

The methods described herein are useful for, e.g., forming, depositing, or growing structures comprising boron and a Group IV element on a substrate. The boron and/or Group IV element formed, deposited, or grown on the substrate may be in the form of a structure, coating, layer, or film. The methods can be useful for the fabrication of FinFETs, traditional planar MOSFETs, pMOS structures, and bipolar transistors, among other structures.

Embodiments of the present disclosure include methods to selectively and epitaxially grow boron-containing and/or Group IV element-containing structures. For example, and when using B-containing and Si-containing process gases, SiB-containing structures grow on exposed regions of crystalline regions of a substrate, and not on exposed regions of dielectric materials on the substrate. Selective SiB containing film growth or deposition may be performed when the substrate surface has exposed thereat more than one material, such as exposed single crystalline silicon surface areas, and features that are covered with dielectric materials such as with SiO and SiN layers. Epitaxial growth or deposition selective to the crystalline silicon surface, while leaving the dielectric features or structures uncoated by the epitaxial deposition material, can be achieved using an etchant (e.g., HCl) during deposition if desired. During deposition, the deposition material forms a crystalline layer on the exposed single crystal, and a polycrystalline or amorphous layer on the exposed dielectric surfaces. If used, the etchant can remove the amorphous or polycrystalline film grown or deposited on the amorphous or polycrystalline features faster than it can remove the epitaxial crystalline film grown or deposited on the exposed crystalline material of the substrate (or the SiB structure never grows on the surface of the dielectric material of the substrate), and thus selective epitaxial net growth or deposition of the SiB structure on the exposed crystalline material of the substrate is achieved.

1 FIG.A 100 is a flow chart showing selected operations of a methodof forming, depositing, or growing an epitaxial structure according to at least one embodiment of the present disclosure. The epitaxial structure formed, deposited, or grown includes, e.g., boron and/or a Group IV element.

100 105 2 The methodbegins with positioning a substrate within a substrate processing chamber at operation. The substrate can have a dielectric material on one or more surfaces of the substrate and a single crystal on one or more surfaces of the substrate. The substrate can be any suitable substrate such as semiconductor wafers, such as crystalline and single crystalline silicon (e.g., Si<100> and Si<111>), silicon germanium, doped or undoped silicon or germanium substrates, silicon on insulator (SOI) substrates, III-V group materials, and patterned or non-patterned substrates, having a variety of geometries (e.g., round, square and rectangular) and sizes (e.g., 200 mm OD, 300 mm OD, 400 mm OD). Surfaces and/or substrates include these materials, as well as films, layers and materials with dielectric, conductive and barrier properties and include polysilicon. Dielectric materials on the substrate can include SiO, SiN, SiON, SiOCN, combinations thereof among other materials. In some examples, the single crystal on the substrate includes a Group IV element.

100 110 110 The methodfurther includes heating the substrate at operation. The heating process of operationcan include heating the substrate at a temperature of about 250° C. or more 300° C. or more and/or about 800° C. or less, such as from about 350° C. to about 750° C., such as from about 400° C. to about 700° C., such as from about 450° C. to about 650° C., such as from about 500° C. to about 600° C., such as from about 500° C. to about 550° C. or from about 550° C. to about 600° C. In at least one embodiment, the temperature can be about 300° C. to about 700° C. Higher or lower temperatures are contemplated.

100 100 In some embodiments, one or more operations of methodcan be performed at a pressure ranging from about 1 Torr to about 100 Torr, such as from about 5 Torr to about 95 Torr, such as from about 10 Torr to about 90 Torr, such as from about 15 Torr to about 85 Torr, such as from about 20 Torr to about 80 Torr, such as from about 25 Torr to about 75 Torr, such as from about 30 Torr to about 70 Torr, such as from about 35 Torr to about 65 Torr, such as from about 40 Torr to about 60 Torr, such as from about 45 Torr to about 55 Torr, such as from about 45 Torr to about 50 Torr or from about 50 Torr to about 55 Torr. In at least one embodiment, one or more operations of methodcan be performed at a pressure of about 5 Torr to about 50 Torr, such as from about 5 Torr to about 20 Torr. Higher or lower pressures are contemplated.

115 115 A first process gas and a second process gas are then flown into the substrate processing chamber at operation. In some examples, a carrier gas and/or an etchant can be flown into the substrate processing chamber before, during, and/or after operation. For example, a carrier gas can be co-flown with one or more of the first process gas, the second process gas, and/or the etchant.

2 2 2 2 6 4 3 2 2 4 2 4 3 In some embodiments, carrier gases can include hydrogen (H), nitrogen (N), a noble gas (e.g., He, Ne, Ar, Kr, and/or Xe), or combinations thereof, among others. Carrier gases may be combined in various ratios during some embodiments of the process. Etchants, which can be in gas form, can be employed to remove B-containing and/or Group IV element-containing structures grown on the exposed dielectric materials which may form on the exposed dielectric materials of the substrate in an amorphous or polycrystalline form faster than it can remove the B-containing and/or Group IV element-containing structures grown or deposited on the exposed crystalline silicon in crystalline form, for example on a single crystal material or on a crystalline material, of the substrate. Etchants useful for such purposes during processes described herein include, but are not limited to, HCl, HF, HBr, Br, SiCl, SiCl, SiHCl, SiHCl, CCl, Cl, GeCl, GeHCl, and combinations thereof.

The first process gas includes at least one boron-containing gas. The at least one boron-containing gas includes haloboranes. The haloborane can be the first boron-containing gas. Haloboranes include compounds having the formula (I):

wherein: 1 1 6 each Ris, independently, hydrogen or a C-Calkyl group (e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, etc.); each X is, independently, a halogen (e.g., F, Cl, Br, or I); and n is 0, 1, or 2.

1 6 The C-Calkyl group can be linear or branched, substituted or unsubstituted, cyclic or acyclic, aromatic or non-aromatic.

3 2 3 2 3 2 3 2 3 2 3 2 3 2 3 2 Illustrative, but non-limiting, examples of haloboranes include boron trifluoride (BF), difluoroborane (BHF), boron trichloride (BCl), dichloroborane (BHCl), boron tribromide (BBr), dibromoborane (BHBr), boron triiodide (BI), diiodoborane (BHl), methyldifluoroborane (CHBF), methyldichloroborane (CHBCl), methyldibromoborane (CHBBr), methyldiiodoborane (CHI), combinations thereof, among others.

In some embodiments, the first process gas can include a second boron-containing gas. Here, the haloborane of formula (I) and the second boron-containing gas can be combined for applications such as boron concentration tuning in a deposited film and selectivity tuning for, e.g., gate-all-around structures (e.g., gate-all-around transistors) having inner spacer regions adjacent to Si open regions. With respect to gate-all-around applications, the epitaxial film can grow from the Si open regions and extend to inner spacer regions (with good wetting between the epitaxial film and inner spacer surface). When the process is over-selective, a gap or a void can form next to the inner spacer surface due to poor wetting with epitaxial film originally grown from Si open regions. Therefore, and in some embodiments, using the first boron-containing gas (i.e., haloborane) with the second boron-containing gas (e.g., B2H6) at various ratios can enable selection of the proper wetting between epitaxial film and the inner spacer (dielectric) surface without void or gap formation.

3 2 6 3 5 4 10 5 9 5 11 6 10 6 12 10 14 The second boron-containing gas can include a borane, an organoborane, combinations thereof, among others. Illustrative but non-limiting, examples of boranes include borane (BH), diborane (BH), triborane (BH), tetraborane (BH), pentaborane (9) (BH), pentaborane (11) (BH), hexaborane (10) (BH), hexaborane (12) (BH), and decaborane (14) (BH).

Organoboranes (also known as alkyl boranes) include compounds having the formula (II):

wherein: 2 1 6 each Ris, independently, a C-Calkyl group (such as those described above); and n is 1, 2, or 3.

3 3 3 2 3 2 3 3 2 2 3 2 2 3 3 2 3 3 6 5 3 Illustrative, but non-limiting, examples of organoboranes include trimethylborane ((CH)B), dimethylborane ((CH)BH), triethylborane ((CHCH)B), diethylborane ((CHCH)BH), tripropylborane ((CHCHCH)B), tributylborane ([CH(CH)]B), triphenylborane ((CH)B), combinations thereof, among others.

3 3 When performing embodiments of the methods described herein, more than one boron-containing gas can be utilized at the same time or at different times. As a non-limiting illustration, BClcan be co-flown with B2H6 or BClcan be flown before B2H6.

The second process gas includes a Group IV element of the periodic table of the elements such as C, Si, Ge, Sn, or combinations thereof, such as Si, Ge, or both. In some embodiments, the Group IV element-containing gases can include silanes, germanes, stannanes, halogenated silanes, halogenated germanes, halogenated stannanes, organosilanes, organogermanes, organostannanes, organohalosilanes, organohalogermanes, organohalostannanes, or combinations thereof.

Silanes, germanes, and stannanes include compounds having the formula (III):

wherein: M is C, Si, Ge, Sn, such as Si or Ge; and x is a non-zero number, such as 1, 2, 3, or 4.

4 2 6 3 8 4 10 4 2 3 8 4 10 Illustrative, but non-limiting, examples of silanes and germanes of formula (III) include silane (SiH), disilane (SiH), trisilane (SiH), tetrasilane (SiH), germane (SiH), digermane (SiH6), trigermane (SiH), tetragermane (GeH), and combinations thereof, among others.

Other Group IV element-containing gases that are useful include compounds having the formula (IV):

wherein: 2 Mis C, Si, Ge, or Sn, such as Si or Ge; 3 1 6 each Ris, independently, a halogen (e.g., F, Cl, Br, or I) or a C-Calkyl group (such as those described above); and y is a non-zero number, such as 1, 2, 3, or 4 and z is, independently, a non-zero number, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

Compounds of formula (IV) include organohalogens, halogenated silanes, halogenated germanes, halogenated stannanes, halogenated organosilanes, organogermanes, organostannanes, organohalosilanes, organohalogermanes, organohalostannanes, or combinations thereof.

3 2 2 3 4 2 6 3 2 2 3 4 2 6 3 2 2 3 4 2 6 3 2 2 3 4 2 6 2 3 4 2 6 2 2 3 4 2 6 3 2 2 3 4 2 6 3 2 2 3 4 2 6 4 4 Illustrative, but non-limiting, examples of halogenated silanes of formula (IV) include fluorosilane (SiHF), difluorosilane (SiHF), trifluorosilane (SiHF), tetrafluorosilane (SiF), hexafluorodisilane (SiF), chlorosilane (SiHCl), dichlorosilane (SiHCl), trichlorosilane (SiHCl), tetrachlorosilane (SiCl), hexachlorodisilane (SiCl), bromosilane (SiHBr), dibromosilane (SiHBr), tribromosilane (SiHBr), tetrabromosilane (SiBr), hexabromodisilane (SiBr), iodosilane (SiHF), diiodosilane (SiHI), triiodosilane (SiHI), tetraiodosilane (Sil), hexaiododisilane (SiI), and combinations thereof, among others. Illustrative, but non-limiting, examples of halogenated germanes of formula (IV) include fluorogermane (GeHsF), difluorogermane (GeH2F), trifluorogermane (GeHF), tetrafluorogermane (GeF), hexafluorodigermane (GeF), chlorogermane (GeHsCl), dichlorogermane (GeHCl), trichlorogermane (GeHCl), tetrachlorogermane (GeCl), hexachlorodigermane (GeCl), bromogermane (GeHBr), dibromogermane (GeHBr), tribromogermane (GeHBr), tetrabromogermane (GeBr), hexabromodigermane (GeBr), iodogermane (GeHF), diiodogermane (GeHI), triiodogermane (GeHI), tetraiodogermane (GeI), hexaiododigermane (GeI), tin chloride (SnCl), tin bromide (SnBr), and combinations thereof, among others.

3 3 3 2 2 3 2 3 3 2 5 3 2 2 4 3 6 2 3 3 3 2 2 3 2 3 3 2 5 3 2 2 4 3 6 2 Illustrative, but non-limiting, examples of organosilanes of formula (IV) include methylsilane ((CH)SiH), dimethylsilane ((CH)SiH), ethylsilane ((CHCH)SiH), methyldisilane ((CH)SiH), dimethyldisilane ((CH)SiH) and hexamethyldisilane ((CH)Si), and combinations thereof, among others. Illustrative, but non-limiting, examples of organogermanes of formula (IV) include methylgermane ((CH)GeH), dimethylgermane ((CH)GeH), ethylgermane ((CHCH)GeH), methyldigermane ((CH)GeH), dimethyldigermane ((CH)GeH) and hexamethyldigermane ((CH)Ge), and combinations thereof, among others.

4 4 When performing embodiments of the methods described herein, more than one Group IV element-containing gas can be utilized at the same time or at different times. As a non-limiting illustration, SiHcan be co-flown with GeH4 or SiHcan be flown before GeH4. In addition, the first process gas (the boron-containing gas) can be flown into the substrate processing chamber before, during, and/or after the second process gas (the Group IV element-containing gas). Additionally, or alternatively, the second process gas can be flown into the substrate processing chamber before, during, and/or after the first process gas. The first process gas can be co-flown with the second process gas.

The first process gas can be flown into the substrate processing chamber at a flow rate that is about 1 sccm or more and/or about 100 sccm or less, such as from about 1 sccm to about 30 sccm, such as from about 1 sccm to about 10 sccm. A higher or lower flow rate of the first process gas is contemplated. The second process gas can be flown into the substrate processing chamber at a flow rate that is about 10 sccm or more and/or about 1000 sccm or less, such as from about 10 sccm to about 500 sccm, such as from about 10 sccm to about 300 sccm. A higher or lower flow rate of the second process gas is contemplated.

100 120 120 115 100 125 The methodfurther includes exposing or introducing the heated substrate with the first process gas and with the second process gas at operation. Operationcan occur during and/or after operation. The methodfurther includes epitaxially and selectively growing or depositing the structure comprising boron and the Group IV element on the single crystal or the crystalline surface at operation. Here, the boron in the epitaxially grown structure comes from the first process gas (boron-containing gas) and the Group IV element(s) in the epitaxially grown structure come from the second process gas (the Group IV element-containing gas).

125 125 125 125 19 3 19 3 21 3 20 3 21 3 The epitaxial and selective growth/deposition occurs while the dielectric features of the substrate remain uncoated (or at least relatively uncoated) by the boron and the Group IV containing structure at the end of operation. In some examples, the concentration of boron in the structure formed in operationis about 1×10atoms/cmor more, such as from about 1×10atoms/cmto about 2×10atoms/cm, such as from about 1×10atoms/cmto about 1×10atoms/cm. Higher or lower concentrations of boron are contemplated. In at least one embodiment, a structure formed by operationincludes an amount of Ge that is from about 0 atomic percent (atomic %) to about 100 atomic %, such as from about 10 atomic % to about 70 atomic %, such as from about 30 atomic % to about 60 atomic %. Higher or lower amounts of Ge are contemplated. In at least one embodiment, a structure formed by operationincludes an amount of Si that is from about 0 atomic % to about 100 atomic %, such as from about 10 atomic % to about 70 atomic %, such as from about 30 atomic % to about 60 atomic %. Higher or lower amounts of Si are contemplated.

In some examples, a growth rate of the structure (e.g., SiB, SiGeB, et cetera) epitaxially deposited is about 10 Å/min or more, such as from about 10 Å/min to about 150 Å/min, such as from about 40 Å/min to about 120 Å/min, such as from about 60 Å/min to about 100 Å/min. Higher or lower growth rates are contemplated.

1 FIG.B 1 FIG.B 150 150 100 is a flow chart showing selected operations of a methodof forming, depositing, or growing an epitaxial structure according to at least one embodiment of the present disclosure. The epitaxial structure formed, deposited, or grown includes, e.g., boron and/or a Group IV element. The methodshown incan be performed in the same or similar manner as methodexcept that a boron-containing gas (i.e., the first process gas) is flown into the chamber and introduced with the substrate prior to co-flowing a Group IV element-containing gas with the boron-containing gas.

150 155 160 155 160 150 105 110 100 100 165 170 175 180 165 170 175 180 150 115 120 100 1 FIG.A Methodbegins with positioning a substrate within the substrate processing chamber and heating the substrate at operationsand, respectively. Operationsandof methodcan be performed in the same, or a similar manner, as described above with respect to operationsandof method, respectively. The substrate processing chamber can be operated at pressures described above with respect to methodof. At operationsand, a first process gas (a boron-containing gas) is flown into the substrate processing chamber and the heated substrate is exposed to the first process gas, respectively. At operationsand, the first process gas (which can be the same or a different boron-containing gas) and the second process gas are co-flown into the substrate processing chamber and the heated substrate is exposed to the first process gas and the second process gas, respectively. Use of the first process gas prior to the second process gas can help passivate the patterned surface of the substrate, especially the dielectric surface of the substrate. Operations,,, andof methodcan be performed in the same, or a similar manner, as described above with respect to operationsandof method, respectively.

150 185 The methodfurther includes epitaxially and selectively growing or depositing the structure comprising boron and the Group IV element on the single crystal or the crystalline surface at operation. Here, the boron in the epitaxially grown structure comes from the first process gas (boron-containing gas) and the Group IV element(s) in the epitaxially grown structure come from the second process gas (the Group IV element-containing gas).

185 185 185 185 19 3 19 3 21 3 20 3 21 3 The epitaxial and selective growth/deposition occurs while the dielectric features of the substrate remain uncoated (or at least relatively uncoated) by the boron and the Group IV containing structure at the end of operation. In some examples, the concentration of boron in the structure formed in operationis about 1×10atoms/cmor more, such as from about 1×10atoms/cmto about 2×10atoms/cm, such as from about 1×10atoms/cmto about 1×10atoms/cm. Higher or lower concentrations of boron are contemplated. In at least one embodiment, a structure formed by operationincludes an amount of Ge that is from about 0 atomic % to about 100 atomic %, such as from about 10 atomic % to about 70 atomic %, such as from about 30 atomic % to about 60 atomic %. Higher or lower amounts of Ge are contemplated. In at least one embodiment, a structure formed by operationincludes an amount of Si that is from about 0 atomic % to about 100 atomic %, such as from about 10 atomic % to about 70 atomic %, such as from about 30 atomic % to about 60 atomic %. Higher or lower amounts of Si are contemplated.

In some examples, a growth rate of the structure (e.g., SiB, SiGeB, et cetera) epitaxially deposited is about 10 A/min or more, such as from about 10 Å/min to about 150 Å/min, such as from about 40 Å/min to about 120 Å/min, such as from about 60 Å/min to about 100 Å/min. Higher or lower growth rates are contemplated.

115 115 A first process gas and a second process gas are then flown into the substrate processing chamber at operation. In some examples, a carrier gas and/or an etchant can be flown into the substrate processing chamber before, during, and/or after operation. For example, a carrier gas can be co-flown with one or more of the first process gas, the second process gas, and/or the etchant.

3 2 6 3 2 6 In some examples, and as described herein, more than one boron-containing gas can be utilized as the first process gas. Here, for example, BCland BHcan be mixed at a certain ratio. For source/drain epitaxial growth on gate-all-around (GAA) structures (e.g., GAA transistors), epitaxial film growth occurs over both the Si surface and the inner spacer (dielectric) surface. The ratio of BCland BHcan be adjusted to tune the selectivity to enable seamless epitaxial film growth over an inner spacer (dielectric) surface without void or gap formation.

Although not shown, further operations may be performed on the substrate. For example, a metal layer can be deposited over the features of the substrate (e.g., a silicon containing single crystal surface, such as the source and drain regions of the substrate) and the substrate and layers formed thereon is thereafter annealed. The metal layer can include, e.g., cobalt, nickel or titanium, among other metals. During an annealing process, the silicon compound layer can be converted to metal silicide layers. For example, when a metal (e.g., cobalt) is deposited as the metal layer, the resulting metal silicide layer is cobalt silicide.

The processes described herein can be used to form, deposit, or grow films used for pMOS, Bipolar (e.g., base, emitter, collector, emitter contact), BiCMOS (e.g., base, emitter, collector, emitter contact) and traditional planar or FinFET CMOS (e.g., channel, source/drain, source/drain extension, elevated source/drain, substrate, strained silicon, silicon on insulator and contact plug). Other embodiments of processes teach the growth of silicon films that can be used as gate, base contact, collector contact, emitter contact, elevated sources/drains, and other uses. Other devices include field effect transistors (FET).

4 FIG. In processes of the present disclosure, boron-containing compounds (e.g., films, layers, and materials) are grown or deposited by chemical vapor deposition (CVD) processes, wherein CVD processes include atomic layer deposition (ALD) processes and/or atomic layer epitaxy (ALE) processes. Chemical vapor deposition includes the use of many techniques, such as plasma-assisted CVD (PA-CVD), atomic layer CVD (ALCVD), organometallic or metalorganic CVD (OMCVD or MOCVD), laser-assisted CVD (LA-CVD), ultraviolet CVD (UV-CVD), hot-wire CVD (HWCVD), reduced-pressure CVD (RP-CVD), and ultra-high vacuum CVD (UHV-CVD). The processes of the present disclosure can be carried out in equipment known in the art of ALE, CVD and ALD processing. The apparatus brings the various gas(es) into contact with a substrate on which the boron-containing and Group IV element-containing structures are grown. An exemplary epitaxy chamber that may be used to grow the boron-containing and Group IV element-containing structures described herein is a Centura® RP EPI chamber available from Applied Materials, Inc., of Santa Clara, California. One exemplary epitaxy chamber is shown in, and described below.

2 FIG. 250 250 251 252 254 252 251 260 254 252 251 251 252 251 252 Various structures can be formed, deposited, or grown via methods described herein.shows an isometric view of a FinFET semiconductor structure, the features of which may be epitaxially grown with the first and second process gases according to at least one embodiment described herein. The FinFET semiconductor structuremay include a substrate, a plurality of fins(only two are shown, but the structure may have more than two fins), a dielectric materialdisposed between adjacent finson the substrate, and a gate electrodedisposed on the dielectric materialand over a portion of each fin. The substratemay be a bulk silicon substrate. The substratemay be doped with a p-type impurity. The plurality of finsmay be fabricated from the same material as the substrate. That is, the plurality of finscan be a source/drain epitaxial fin grown by methods described herein.

254 252 254 258 260 252 258 260 252 258 260 2 FIG. The dielectric materialmay form isolation regions, such as shallow trench isolation (STI) regions, and may be fabricated from silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, or any other suitable dielectric material. As shown in, each of the plurality of finsextends a distance above the upper surface of the dielectric material. A gate dielectricis formed between the gate electrodeand the plurality of fins. The gate dielectricfacilitates electrical isolation between the gate electrodeand the plurality of fins. The gate dielectricmay be fabricated from silicon nitride, silicon oxide, hafnium oxide, hafnium silicon oxynitride, hafnium silicate, hafnium silicon oxide, or any other suitable gate dielectric material. The gate electrodemay be fabricated from polysilicon, amorphous silicon, germanium, silicon germanium, metals, or metal alloys.

3 FIG.A 334 336 336 depicts a cross section for a traditional planar MOSFET according to some embodiments. After forming a spaceron both sides of a dummy gate, a portion of the substrate or of the fin is etched away followed by wet-cleaning of the substrate, to produce a recess within which the boron-containing and Group IV element-containing structure is epitaxially grown according to the methods described herein and for use as the source/drain. The boron-containing and Group IV element-containing structure epitaxially grows to mimic the crystal lattice of the exposed substrate or fin surface and maintains this arrangement as the structure grows with thickness. Subsequent to this source drain formation, and after several intermediate steps, the dummy gateis eventually replaced with an actual metal gate electrode.

332 332 330 332 332 3 FIG.A 19 3 19 3 21 3 20 3 21 3 An epitaxial structureis selectively deposited within the source/drain region according to embodiments described herein. Selective growth of the epitaxial structuremay be performed when a substrate surfacehas exposed thereat more than one material, such as exposed single crystalline silicon surface areas, and features that are covered with dielectric materials such as with SiO and SiN layers. The epitaxial structureis composed of, for example, doped SiGe containing layers located to either side of the gate in the device depicted byand having a germanium concentration of, for example, about 0 atomic % to about 100 atomic %, such as from about 10 atomic % to about 70 atomic %, such as from about 30 atomic % to about 60 atomic %. The epitaxial structurecan also include a dopant (boron) concentration of, e.g., about 1×10atoms/cmor more, such as from about 1×10atoms/cmto about 2×10atoms/cm, such as from about 1×10atoms/cmto about 1×10atoms/cm.

340 332 In some embodiments, a boron-doped SiGe structurecan, using the methods described herein, be formed on top of an existing B-doped SiGe source/drain layer (e.g., epitaxial structure) to form a contact layer. This contact layer reduces the Schottky barrier between B-doped SiGe source/drain and the metal electrode, and provides lower contact resistivity. In this embodiment, the existing B-doped SiGe source/drain can be made by the same or similar methods described herein, or by other methods.

3 FIG.B 2 FIG. 350 358 366 366 252 depicts the cross section for a FinFETaccording to some embodiments. For FinFET source/drain epi film which can be grown by methods described herein, a dielectric materialis utilized as a sidewall to confine an epitaxial structure(or epitaxial film). The epitaxial structuregrown by methods described herein is a plurality of fins (the plurality of fins can correspond to the plurality of finsof).

3 FIG.B 2 FIG. 366 352 354 351 254 254 366 363 362 358 366 362 358 366 362 358 366 366 366 366 As shown in, the epitaxial structureis deposited on a surfaceof a substrateand extending over an upper surfaceof the dielectric material(the dielectric materialis also shown in). Each epitaxial structurehas a surfacethat is recessed from a surfaceof the dielectric material. The epitaxial structuremay also be deposited on the surfaceof the dielectric material, and an etch back process may be performed to remove the epitaxial structuredeposited on the surfaceof the dielectric material. The epitaxial structuremay be the source or drain of a FinFET device and may be a boron and Group IV element-containing material. The epitaxial structuremay be formed by an epitaxial deposition process described herein in an epitaxial process chamber available from Applied Materials, Inc. In one embodiment, the epitaxial structureis silicon doped with boron and the FinFET device is a p-type FET. In another embodiment, the epitaxial structureis silicon germanium doped with boron, and the FinFET device is a p-type FET.

366 366 366 3 FIG.B 19 3 19 3 21 3 20 3 21 3 The epitaxial structureis selectively grown within the source/drain region according to embodiments described herein. Selective growth may be performed when the substrate surface has exposed thereat more than one material, such as exposed single crystalline silicon surface areas, and features that are covered with dielectric materials such as with SiO and SiN layers. The epitaxial structureis composed of, for example, doped SiGe containing layers located to either side of the gate in the device depicted byand having a germanium concentration of, for example, about 0 atomic % to about 100 atomic %, such as from about 10 atomic % to about 70 atomic %, such as from about 30 atomic % to about 60 atomic %. The epitaxial structurecan also include a dopant (boron) concentration of, e.g., about 1×10atoms/cmor more, such as from about 1×10atoms/cmto about 2×10atoms/cm, such as from about 1×10atoms/cmto about 1×10atoms/cm.

4 FIG. 400 is a cross-sectional view of a substrate processing chamberthat may be used to perform one or more operations of the methods described herein. It is contemplated that other processing chambers can be utilized.

400 402 404 406 402 412 414 412 402 416 410 414 402 430 410 410 412 The substrate processing chamberincludes a chamber body, support systems, and a controller. The chamber bodyincludes an upper portionand a lower portion. The upper portionincludes the area within the chamber bodybetween the upper domeand a substrate. The lower portionincludes the area within the chamber bodybetween a lower domeand the bottom of the substrate. Deposition processes generally occur on the upper surface of the substrateexposed to and within the upper portion.

404 400 406 404 400 404 406 The support systemincludes components used to execute and monitor pre-determined processes, such as the growth or deposition of thin films in the substrate processing chamberas described herein. The controlleris coupled to the support systemand is adapted to control the substrate processing chamberand support system. The controllerincludes a central processing unit (CPU), a memory, and support circuits.

400 435 400 435 410 426 400 423 430 435 416 430 The substrate processing chamberincludes a plurality of heat sources, such as lamps, which are adapted to provide thermal energy to components positioned within the substrate processing chamber. For example, the lampsmay be adapted to provide thermal energy to the substrate, a susceptorfor supporting a substrate in the substrate processing chamber, and/or a preheat ring. The lower domemay be formed from an optically transparent material, such as quartz, to facilitate the passage of thermal radiation therethrough. It is contemplated that lampsmay be positioned to provide thermal energy through the upper domeas well as through the lower dome.

402 476 478 420 450 412 402 421 450 412 450 410 The chamber bodyincludes a plurality of plenums formed therein. The plenums are in fluid communication with one or more gas sources, such as a carrier gas, and one or more precursor sources, such as process gases (e.g., Group IV element-containing gases and boron-containing gases). For example, a first plenummay be adapted to provide a process gastherethrough into the upper portionof the chamber body, while a second plenummay be adapted to exhaust the process gasfrom the upper portion. In such a manner, the process gasmay flow parallel to an upper surface of the substrate.

400 482 480 482 400 480 In cases where a liquid precursor (e.g., tetrasilane) is used, the substrate processing chambermay include a liquid vaporizerin fluid communication with a liquid precursor source. The liquid vaporizeris to be used for vaporizing liquid precursors to be delivered to the substrate processing chamber. While not shown, it is contemplated that the liquid precursor sourcemay include, for example, one or more ampoules of precursor liquid and solvent liquid, a shut-off valve, and a liquid flow meter (LFM). As an alternative to the liquid vaporizer, a bubbler may be used to deliver the liquid precursor(s) to the chamber. In such cases, an ampoule of liquid precursor is connected to the process volume of the chamber through a bubbler.

432 414 402 432 410 432 427 426 427 437 427 426 460 427 431 442 427 410 427 429 427 431 A substrate support assemblyis positioned in the lower portionof the chamber body. The substrate support assemblyis illustrated supporting a substratein a processing position. The substrate support assemblyincludes a susceptor supportformed from an optically transparent material and the susceptorsupported by the susceptor support. Support pinscouple the susceptor supportto the susceptor. A shaftof the susceptor supportis positioned within a shroudto which lift pin contactsare coupled. The susceptor supportis rotatable in order to facilitate the rotation of the substrateabout its center during processing. Rotation of the susceptor supportis facilitated by a motor, or a belt and motor (not shown). An actuatoris coupled to the susceptor supportand is used to lift and retract the shaft in order to raise and lower the support. The shroudis generally fixed in position, and therefore, does not rotate during processing.

433 427 433 442 410 410 426 442 427 433 442 423 440 402 423 402 410 410 423 450 450 402 420 423 415 416 417 430 Lift pinsare disposed through openings (not labeled) formed in the susceptor support. The lift pinsare vertically actuatable by contact with moveable lift pin contactsand are adapted to contact the underside of the substrateto lift the substratefrom a processing position (as shown) to a substrate removal position, and to support a newly loaded substrate from a loading position to the processing position on the susceptor. Moving of lift pin contactsup and down, or stationary positioning of them when the susceptor supportmoves up or down, causes the bottoms of the lift pinsto come into contact with the lift pin contacts, so that they stop moving downward while the support continues to move downward. The preheat ringis removably disposed on a lower linerthat is coupled to the chamber body. The preheat ringis disposed around the internal volume of the chamber bodyand circumscribes the substratewhile the substrateis in a processing position. The preheat ringfacilitates preheating of a process gasas the process gasenters the chamber bodythrough the first plenumadjacent to the preheat ring, and reduces the size of the opening between the upper and lower volumes of the chamber. The central window portionof the upper domeand the bottom portionof the lower domeare formed from an optically transparent material such as quartz.

3 Etchants can be co-flowed with the process gases to further improve deposition or growth selectivity. The etchants are not limited to hydrogen chloride, and can contain halogen, germanium, and/or silicon in the molecules. In situ doping of the deposited materials can be achieved at the same time by co-flowing dopant-containing species such as BCl(for p-type) with the Group IV element-containing gases.

400 400 A computer system may perform the instructions provided in a non-transitory computer readable medium. The non-transitory computer readable medium can contain instructions to perform the methods described herein. Alternately, the instructions to perform the methods described herein may be added to the non-transitory computer readable medium. The non-transitory computer readable medium can include instructions that cause a computer system to control a substrate processing apparatus to perform processes described herein. The substrate processing chambercan be a part of the substrate processing apparatus. The computer system can be connected to one or more of the substrate processing chamber, to valves that regulate the process gases, carrier gases, etchant gases, et cetera, and to switches that regulate temperature and pressure of the various components of the substrate processing apparatus.

410 426 400 423 435 450 400 420 400 420 In use, and according to some embodiments, the substratelocated on the susceptoris positioned within the substrate processing chamber. The substrate is heated by, e.g., preheat ringand/or lamps. The process gas(e.g., first process gas and/or second process gas) are flown into the substrate processing chamberthrough the first plenum. Carrier gases and/or etchants can also be flown into the substrate processing chamberthrough the first plenum. Exposure of the heated substrate to the process gases enables formation of a boron-containing and Group IV element-containing structure on the substrate.

Embodiments of the present disclosure can be further understood by the following non-limiting examples. The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use aspects of the present disclosure, and are not intended to limit the scope of aspects of the present disclosure.

2 6 3 2 6 3 2 2 4 2 In a non-limiting example, SiGeB films were epitaxially grown on a substrate having a single crystal and a dielectric material formed thereon. Three different boron source gases (first process gases) were utilized: BHalone, BClalone, or a mixture of BHand BCl. The SiGeB was grown utilizing one of the first process gases, two second process gases (SiClHand GeH), Has a carrier gas, and HCl as an etchant. Suitable flow rates of the first process gas, second process gas, etchant, and carrier gas were selected. The substrate was heated at suitable temperatures and the chamber was pressurized at suitable pressures.

2 6 20 3 When using BHalone as the first process gas, the selective growth rate of the SiGeB film was determined to be about 11 Å/min. The SiGeB film grown had a boron concentration of about 2×10atoms/cmand a Ge concentration of about 54 atomic %.

3 3 20 3 Use of BClalone as the first process gas showed significant improvements in the growth rate and the SiGeB film relative to B2H6 alone. Here, the selective growth rate of the SiGeB film was determined to be about 40 A/min. The SiGeB film grown had a boron concentration of about 4.3×10atoms/cmand a Ge concentration of about 56 atomic %. Relative to the use of B2H6 alone, the utilization of BClresulted in a higher selective growth rate while using less HCl etchant and a higher concentration of boron in the formed SiGeB film.

2 6 3 2 6 2 6 2 6 3 2 6 3 20 3 Use of a mixture of BHand BClas the first process gas also showed significant improvements over BHalone. Here, the selective growth rate of the SiGeB film was determined to be about 40 A/min. The SiGeB film grown had a boron concentration of about 5.2×10atoms/cmand a Ge concentration of about 48 atomic %. Relative to the use of BHalone, utilization of the mixture of BHand BClresulted in a higher selective growth rate of the SiGeB film while using less HCl etchant and a higher concentration of boron in the resulting SiGeB film. In addition, the SiGeB film grown showed good wetting with the dielectric materials indicating that the SiGeB film remains next to the dielectric surface. This result also indicated that the mixture of BHand BClcan be utilized for gate all around structures.

In another non-limiting example, SiGeB pMOS films were epitaxially grown on a substrate having a single crystal and a dielectric material formed thereon. Table 1 shows certain parameters and results of the epitaxial process. The substrate was heated at suitable temperatures and the chamber was pressurized at suitable pressures. Comparative examples are indicated by C.Ex.

TABLE 1 C. Ex. 1 C. Ex. 2 Ex. 1 Ex. 2 Ex. 3 Process parameters Si source 2 2 SiClH 4 SiH 2 2 SiClH 4 SiH 4 SiH Ge source 4 GeH 4 GeH 4 GeH 4 GeH 4 GeCl B source 2 6 BH 2 6 BH 3 BCl 3 BCl 3 BCl Etchant HCl HCl HCl HCl — SiGeB film 20 3 B concentration, ×10atoms/cm  <3 —  >5  >5  >5 Growth rate, Å/min <10 — >40 >100 >100

2 6 20 3 The film of comparative example 1 (C.Ex. 1) showed early nucleation of BH, low growth rates, and low boron concentrations. Comparative example 2 (C.Ex. 2) showed poor selectivity. In contrast, the Examples (Ex. 1, Ex. 2, and Ex. 3) showed significant improvements in the boron concentration and growth rates. For example, each of Ex. 1-3 showed an improvement in boron concentration to about 5×10atoms/cm. Growth rates also significantly improved to greater than about 40 (Ex. 1) or greater than about 100 (Ex. 2 and Ex. 3). Ex. 3 showed that the process can be free of etchant while still enabling, e.g., high selectivity. The examples also indicated that the methods described herein can be utilized to achieve, e.g., bottom-up growth of SiGeB films, among other advantages.

The methods described herein enable selective growth of boron-doped structures with almost complete selectivity to deposit on crystalline surfaces of the substrate. The methods advantageously provide, e.g., improved boron concentrations and selectivity relative to conventional epitaxial processes. In addition, the methods described herein can be utilized for pMOS-type applications.

The present disclosure provides, among others, the following embodiments, each of which can be considered as optionally including any alternate embodiments:

positioning the substrate within a substrate processing chamber, the substrate having a dielectric material and a single crystal formed thereon, the single crystal comprising a Group IV element; heating the substrate at a temperature of about 300° C. or more; the first process gas comprises at least one boron-containing gas, the at least one boron-containing gas comprising a haloborane of formula: flowing a first process gas and a second process gas into the substrate processing chamber, wherein: Clause 1. A method of depositing a structure comprising boron and a Group IV element on a substrate, the method comprising:

1 1 6 wherein: each Ris, independently, hydrogen or a C-Calkyl group; each X is a halogen; and n is 0, 1, or 2; and the second process gas comprises at least one Group IV element-containing gas; and 20 3 exposing the substrate to the first process gas and the second process gas to epitaxially and selectively deposit the structure comprising boron and the Group IV element on the single crystal, the structure having a boron concentration of about 3×10atoms/cmor more.

Clause 2. The method of Clause 1, further comprising flowing an etchant gas into the substrate processing chamber before flowing the first and second process gases, during the flowing of the first and second process gases into the substrate processing chamber, or both.

Clause 3. The method of Clause 1 or Clause 2, wherein the first process gas is flown into the substrate processing chamber and is exposed to the substrate prior to flowing the second process gas into the substrate processing chamber.

Clause 4. The method of any one of Clauses 1-3, further comprising co-flowing the first process gas and the second process gas into the substrate processing chamber after exposing the substrate to the first process gas.

Clause 5. The method of any one of Clauses 1-4, wherein a carrier gas is flown into the substrate processing chamber with the first process gas or the second process gas.

Clause 6. The method of any one of Clauses 1-5, wherein the second process gas comprises Si, Ge, or a combination thereof.

Clause 7. The method of any one of Clauses 1-6, wherein: n is 0; and each X is, independently, Cl or Br.

1 1 6 Clause 8. The method of any one of Clauses 1-7, wherein: each Ris, independently, hydrogen or a C-Calkyl group; n is 1 or 2; and each X is, independently, Cl or Br.

Clause 9. The method of any one of Clauses 1-8, wherein the at least one boron-containing gas further comprises a borane, an organoborane, or a combination thereof.

3 2 6 3 5 4 10 5 9 5 11 6 10 6 12 10 14 when the boron-containing gas further comprises a borane, the borane comprises borane (BH), diborane (BH), triborane (BH), tetraborane (BH), pentaborane (9) (BH), pentaborane (11)) (BH), hexaborane (10) (BH), hexaborane (12) (BH), decaborane (14) (BH), or combinations thereof; or 3 3 3 2 3 2 3 3 2 2 3 2 2 3 3 2 3 3 6 5 3 when the boron-containing gas further comprises an organoborane, the organoborane comprises trimethylborane ((CH)B), dimethylborane ((CH)BH), triethylborane ((CHCH)B), diethylborane ((CHCH)BH), tripropylborane ((CHCHCH)B), tributylborane ([CH(CH)]B), triphenylborane ((CH)B), or combinations thereof. Clause 10. The method of Clause 9, wherein:

positioning the substrate within a substrate processing chamber, the substrate having a dielectric material and a single crystal formed thereon, the single crystal comprising Si, Ge, or a combination thereof; heating the substrate at a temperature of about 300° C. to about 700° C.; and the first process gas comprises at least one boron-containing gas, the at least one boron-containing gas comprising a haloborane having the formula: flowing a first process gas, a second process gas, and a carrier gas into the substrate processing chamber, wherein: epitaxially and selectively growing the structure comprising boron and the Group IV element on the single crystal, comprising: Clause 11. A method of epitaxially and selectively growing a structure comprising boron and a Group IV element on a substrate, the method comprising:

1 1 6 wherein: each Ris, independently, hydrogen or a C-Calkyl group; each X is a halogen; and n is 0, 1, or 2; the second process gas comprises at least one Group IV element-containing gas; and 2 2 the carrier gas comprises H, N, or a combination thereof; and 20 3 exposing the substrate to the first process gas and the second process gas to epitaxially and selectively grow the structure, the structure having a boron concentration of about 3×10atoms/cmor more.

Clause 12. The method of Clause 11, further comprising flowing an etchant gas into the substrate processing chamber while epitaxially and selectively growing the structure comprising boron and the Group IV element on the single crystal.

Clause 13. The method of Clause 11 or Clause 12, wherein: n is 0; and each X is, independently, Cl or Br.

3 2 6 3 5 4 10 5 9 5 11 6 10 6 12 10 14 Clause 14. The method of any one of Clauses 11-13, wherein the at least one boron-containing gas further comprises borane (BH), diborane (BH), triborane (BH), tetraborane (BH), pentaborane (9) (BH), pentaborane (11) (BH), hexaborane (10) (BH), hexaborane (12) (BH), decaborane (14) (BH), or combinations thereof.

Clause 15. The method of any one of Clauses 11-14, wherein the at least one Group IV element-containing gas has the formula:

1 2 3 1 6 wherein: each of Mand Mis, independently, Si or Ge; each Ris, independently, a halogen or a C-Calkyl group; x is 1, 2, 3, or 4; y is 1, 2, 3, or 4; and z is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

Clause 16. The method of any one of Clauses 11-15, wherein the at least one Group IV element-containing gas comprises a silane, a germane, or a combination thereof having the formula:

1 wherein: Mis Si or Ge; and x is 1, 2, 3, or 4.

Clause 17. The method of any one of Clauses 11-16, wherein the first process gas is flown into the substrate processing chamber and is exposed to the substrate prior to flowing the second process gas into the substrate processing chamber.

Clause 18. The method of Clause 17, further comprising co-flowing the first process gas and the second process gas into the substrate processing chamber after flowing the first process gas into the substrate processing chamber and exposing the first process gas to the substrate.

positioning the substrate within a substrate processing chamber, the substrate having a dielectric material and a single crystal formed thereon; heating the substrate at a temperature of about 300° C. to about 700° C.; and flowing a first boron-containing gas into the substrate processing chamber, the first boron-containing gas comprising a haloborane; exposing the substrate with the first boron-containing gas; co-flowing a second boron-containing gas and at least one Group IV element-containing gas into the substrate processing chamber, the first boron-containing gas and the second boron-containing gas being the same or different; and 20 3 exposing the substrate with the second boron-containing gas and the Group IV element-containing gas to epitaxially and selectively grow the structure, the structure having a boron concentration of about 3×10atoms/cmor more. epitaxially and selectively growing the structure comprising boron and the Group IV element on the single crystal, comprising: Clause 19. A method for epitaxially and selectively growing a structure comprising boron and a Group IV element on a substrate, the method comprising:

3 2 6 3 5 4 10 5 9 5 11 6 10 6 12 10 14 the second boron-containing gas comprises borane (BH), diborane (BH), triborane (BH), tetraborane (BH), pentaborane (9) (BH), pentaborane (11) (BH), hexaborane (10) (BH), hexaborane (12) (BH), decaborane (14) (BH), or combinations thereof; and 4 2 6 3 8 4 10 4 2 6 3 8 4 10 the at least one Group IV element-containing gas comprises silane (SiH), disilane (SiH), trisilane (SiH), tetrasilane (SiH), germane (SiH), digermane (SiH), trigermane (SiH), tetragermane (GeH), or combinations thereof. Clause 20. The method of Clause 19, wherein:

As is apparent from the foregoing general description and the specific embodiments, while forms of the embodiments have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby. Likewise, the term “comprising” is considered synonymous with the term “including.” Likewise whenever a formulation, a composition, an element or a group of elements is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same formulation, composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “Is” preceding the recitation of the formulation, composition, element, or elements and vice versa, e.g., the terms “comprising,” “consisting essentially of,” “consisting of” also include the product of the combinations of elements listed after the term.

References cited herein are incorporated by reference herein in their entirety to indicate the state of the art as of their publication or filing date and it is intended that this information can be employed herein, if needed, to exclude specific embodiments that are in the prior art.

For purposes of this present disclosure, and unless otherwise specified, all numerical values within the detailed description and the claims herein are modified by “about” or “approximately” the indicated value, and consider experimental error and variations that would be expected by a person having ordinary skill in the art. For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, within a range includes every point or individual value between its end points even though not explicitly recited. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

As used herein, the indefinite article “a” or “an” shall mean “at least one” unless specified to the contrary or the context clearly indicates otherwise. For example, embodiments comprising “a process gas” include embodiments comprising one, two, or more process gases, unless specified to the contrary or the context clearly indicates only one process gas is included.

While the foregoing is directed to embodiments of the present disclosure, other and further aspects of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

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Filing Date

October 10, 2025

Publication Date

February 5, 2026

Inventors

Xuebin LI
Sathya CHARY
Joe MARGETIS

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METHODS OF EPITAXIALLY GROWING BORON-CONTAINING STRUCTURES — Xuebin LI | Patentable